good morning from cairo. Welcome to this week. Breaking this morning, u.S. Warships in position for a possible strike on syria. Accused of using chemical weapons, has syria finally crossed a red line? It's very trolesome. Are we on the brink of war? Plus in egypt, anarchy on the streets of this key u.S. Ally. We're here on the ground and anchoring from the region with all the breaking details. And 50 years later, remembering a day that changed the nation. What was at stake that day? The future of america. Was dr. King's dream fulfilled? The powerhouse roundtable weighs in on that and all the week's politics. It's all right here this sunday morning. From abc news, a special edition of "this week" with martha raddatz in cairo. And jonathan karl in washington. Starts right now. Good morning, george is off today. We're reporting from a region on the brink, and all eyes are on syria, where an apparent chemical weapons attack could lead to american military action. Here in cairo, we're just 100 miles from the mediterranean sea where u.S. Warships are now at the ready. This morning, officials tell abc news that u.S. Navy destroyers now in the mediterranean could be used to carry out limited military strikes. Cruise missile strikes, designed to deter or prevent another chemical attack by the assad regime. If this week's suspected attack is verified. This is clearly a big event. Of grave concern. That starts getting to some core national interest that the united states has. President obama has so far been unwilling to militarily intervene in syria, despite the deaths of more than 100,000 people and a vow he made more than one year ago. That's a red line for us. And that there would be enormous consequences if we start seeing movement on the chemical weapons front. With that line possibly CROSSED, SENATOR john McCain fears u.S. Credibility is now at stake. You can't look at those pictures without being deeply moved. Are we going to just let that go on? So how will president obama respond? The white house is considering a number of options. And for more on that, let's bring in jonathan karl in washington. Jon, what can you tell us? The president ordered the national security team to drop options for a possible military strike on syria. One official says there's, quote, a strong suspicion that the assad regime is responsible for what appears to be a large-scale chemical attack on civilians, including many children. The intelligence community is still gathering evidence, but the senior official tells me there are strong indications implicating the syrian government. The attack was on rebel-held territory and apparently done using rockets, rockets the rebels do not possess. But there's a divide on how to respond, although an official says if there is a strike, it must be done timely. Soon enough to prevent another chemical attack. The white house does not want to act alone. U.S. Officials are back channeling through the u.N. To see if russia could be convinced to agree to a resolution. They have veto power at the security council. If there's no u.N. Authorization, the u.S. Would lead a possible strike. But one senior official tells me, quote, we do not want to do anything on our own. U.S. Allies must commit both resources and political will. We'll have more from washington in a few moments. But first back to the region, martha. Thanks, jon. Let's bring in kerl steve ganyard, a veteran fighter pilot who flew missions in the gulf war and saw the policy side as a deputy secretary of state. Welcome, colonel. Let's get to the question about the cruise missile strikes. The white house said there will be no boots on the ground. How would these work out of the mediterranean? There are a couple ways it could be done. One is by launching them from ships at sea out in the eastern mediterranean or from submarines. We've got to remember what a cruise missile is. It's a long, 20-foot sort of flying torpedo, and has wings and a little jet engine that allows it to fly at low altitudes over the sea. It can fly through mountain canyons and hit with accuracies where you can pick third window on the left. So that kind of accuracy is good. But we have to remember they're small warheads, and not a lot of these missiles. Right up front, if it's low-risk, we're going to be prescribed in the amount of military force we can apply. One of the things we have talked to people about, is there might be missions, fighter jets. I know you have gone on these missions before. This is very different because the fighter jets would not actually enter syrian air space, how does that work and why wouldn't they? The idea is the syrians have created a sanctuary where it's a dome over syria. The president wants low-risk to u.S. Personnel. He does not want u.S. Aircraft flying into, penetrating that dome, that sanctuary that the syrians have created. So we will use our aircraft and bombers to launch glide weapons, standoff weapons from well outside the syrian surface to air missile threat so our air crews will not be in any danger and can return home safely. Let's talk about targets. Obviously this is about chemical weapons. You can't really go after chemical weapons without creating more danger, can you? So talk a little bit about the targets and what the u.S. And whoever joins in could do. That's right. You would think, chepmical weapons, go in and destroy the chemical weapons with bombs. But chemical weapons can only be destroyed with very, very sensitive technology that incinerates them or chemically neutralizes them. You can't drop a bomb on a bunker and expect it to neutralize the capabilities. Bomb the bunker and throw them all over the desert and perhaps throw these containers of some nerve gas or some sort of agent that could be picked up by somebody and used in a terrorist attack. Highly unlikely we will go after the sites themselves that contain the weapons, but we'll probably attack things that allow them to ploy -- employ these kinds of weapons. Things like airfields, like command and control facilities, military headquarters. Perhaps airplanes, airfields, those things that would allow the syrian military to employee gas against its citizens. From what you've heard, does this seem like a symbolic attack, or could it actually do some good? I think we need to temper our expectations. This is a very limited attack, what's being discussed is a very limited military attack. I think that the best we could hope for is to deter mr. Assad from using the chemical weapons against his people again. But it's not going to help with the refugee problem. Worst case, it could lead to, he would shrug off the attack, precipitate military attacks and perhaps drag us into a larger middle east conflict, which is something the white house seems quite keen to avoid. Thanks so much for joining us, colonel ganyard.

This transcript has been automatically generated and may not be 100% accurate.

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